微量元素对牛粪低温厌氧发酵的影响

为考察较低温度(<17℃)条件下添加微量金属元素对厌氧发酵产气量的影响,在发酵底物TS(含固率)为10%下采用10 L玻璃瓶作反应器,以牛粪为原料,向厌氧生物反应器中分别添加MnSO4、FeSO4·7H2O、电解锰渣,分析了厌氧消化系统运行过程中的产气量、COD(化学需氧量)和pH的变化。结果表明,锰元素能促进低温下牛粪的厌氧发酵,加速反应启动。当添加6 g MnSO4、100 g电解锰渣时,单位质量VS产气率分别为0.26 mL/g和0.64 mL/g,添加6 g FeSO4·7H2O与空白对照组均未见明显产气。     

电解锰渣中锰的浸出条件及特征

采用水洗-酸解法回收电解锰渣中锰,探讨了清水量、酸量以及温度在不同阶段对锰浸(洗)出条件的影响,分析了回收锰的主要因素及浸出特征。实验结果表明,50 g电解锰渣经m渣∶m水=1∶10的清水水洗后,采用10%的硫酸在70℃的水浴温度下酸解2 h,Mn2+浸出量为1.673 g,回收率达到97.3%,而温度和酸度对锰离子的浸出影响明显,酸度调控可有效分离酸浸锰液中金属成分,为减少电解锰渣环境污染的同时,实现电解锰渣资源化利用。     

钢渣吸附处理苯酚废水的研究

采用恒温振荡的方法,考察了钢渣粒径、吸附温度、振荡速度、溶液pH值、溶液初始浓度对苯酚去除率的影响。结果表明,在粒径为120~180目、pH=4.0、苯酚溶液浓度在500 mg/L以内、苯酚/钢渣质量比为1∶1 000时吸附效果最好。钢渣对苯酚的吸附能较好地符合Langmuir和Freundlich吸附等温线,线性相关系数分别为0.9971和0.9916,吸附机理为表面吸附。     

利用高炉水淬渣制作多孔吸声材料的研究

为了促进高炉炼铁水淬渣的二次利用,研究了以高炉炼铁水淬渣为原料,以硅微粉或水泥为粘结剂,采用压制成型方法制作的多孔吸声材料的吸声性能及力学性能。结果表明:用颗粒状的高炉炼铁水淬渣制作的多孔吸声材料具有良好的吸声性能,其平均吸声系数可以达到0.70以上;材料的抗压强度可以达到3.0 MPa以上。     

Phytoavailability and extractability of potassium,magnesium and manganese in calcareous soil amended with olive oil wastewater

Abstract

Land disposal of olive oil wastewater using it as a soil amendment requires a knowledge of the effects that its application may produce on the status of the mineral nutrients in the plant‐soil system. A pot experiment using calcareous soil was performed in a growth chamber to examine the effects of olive oil wastewater on the availability and postharvest soil extractability of K, Mg and Mn. The experiment included 6 treatments: two rates of olive oil wastewater, two mineral fertilizer treatments containing K (which supplied K in amounts equivalent to the K supplied by the olive oil wastewater treatments), a K‐free mineral fertilizer treatment, and a control. The pots were sown with ryegrass as the test plant, harvesting 3 times at intervals of one month. Olive oil wastewater has demonstrated a considerable capacity for supplying K that can be assimilated by the plant, tending in fact to surpass the mineral potassium fertilizer tested. The application of olive oil wastewater tends to reduce the concentration of Mg in the plant, similarly to the effect of adding mineral potassium fertilizer. An enhancement of Mn availability takes place in the soil amended with olive oil wastewater, which on occasion has produced Mn concentrations in plant that could be considered phytotoxic or at least excessive. After harvesting, we observed an increase in the amount of exchangeable K in soil with added industrial wastewater. However, these increases are lower than those in soil treated with mineral potassium fertilizer. The levels of exchangeable, carbonate‐bound, organic‐bound and residual Mg in soil were higher in treatments incorporating olive oil wastewater than in those with added mineral K, with the opposite tendency occurring in the amount of Fe‐Mn oxides‐bound Mg in soil. Treatments based on olive oil wastewater, especially in high doses, increased the amount of exchangeable and carbonate‐bound Mn in soil, in comparison with treatments adding mineral fertilizers with or without K. In contrast, the addition of industrial wastewater caused a drop in the amount of Fe‐Mn oxides‐bound and organic‐bound Mn in soil.     

钢渣掺量对泡沫混凝土砌块性能的影响

泡沫混凝土是一种环保、节能的保温隔热材料,以其优良的保温性能,受到越来越多研究者的关注。对钢渣的特性进行了分析测试,对钢渣不同掺量对泡沫混凝土砌块特性的影响进行了研究,结果表明,采用添加5％～35％钢渣所制备的钢渣泡沫混凝土砌块,其密度等级为JC／T1062—2007中的B10级,掺人5％、15％钢渣的泡沫混凝土抗压强度达到A3．5等级,掺人25％、35％钢渣的泡沫混凝土抗压强度达到A2．5等级。随着钢渣掺量的增大,抗压强度、抗折强度降低,吸水率增大。在同一钢渣掺量的情况下,泡沫混凝土砌块的抗压强度变化率增加显著,而且随着钢渣的加入量升高而增大。钢渣的加入有利于提高泡沫混凝土砌块的后期抗压强度。     

粗MnSO4溶液中MnS2O6的去除条件研究

用软锰矿吸收SO2生成MnSO4时会伴随有副产物MnS2O6生成。产品中MnS2O6的存在会降低硫酸锰产品质量,同时会缓慢释放出SO2气体污染环境。本文用单因素实验方法研究了粗MnSO4溶液中MnS2O6的最优去除条件。研究结果显示,软锰矿用量为12.2 g,硫酸加入量为20 mL、反应温度100℃、反应时间3 h、搅拌速度500 r/min,MnS2O6的去除率可达91%以上。其最终产品能达到GB1622-1986一级品标准。     

不同培养条件下锰过氧化物酶(MnP)的合成及其对甲基橙的降解

高效、大规模、低成本合成木质素降解酶是直接采用其降解难降解有机污染物所必须解决的问题.对锰过氧化物酶(MnP)降解甲基橙和在非灭菌的反应器中连续合成MnP的可行性进行考察.结果表明,在采用2 mmol H2O2和1.5 mmol MnSO4的降解体系中,获最大脱色效果,且100、200和300 U/L的MnP可在8h内将甲基橙分别脱色18％、23％和35％;在非灭菌的反应器水平上实现了固定化培养的P.chrysosporium连续23 d合成MnP,但MnP酶活仅为2～ 23 U/L,难以酶解甲基橙;然而,在摇瓶培养条件下固定化的P.chrysosporium合成的MnP却能达1 152 U/L.因此,直接采用MnP对污染物进行降解以及在非灭菌的反应器中持续合成MnP是可行的,但就在非灭菌条件下如何提高MnP的合成量还有待开展深入的研究.     

高炉渣对Cd~(2+)的吸附性能

采用包头钢铁集团炼铁厂的高炉渣为吸附剂(粒径0.154 nm)对Cd2+进行吸附,运用SEM技术对吸附剂进行了表征,研究了初始Cd2+质量浓度、吸附剂加入量、吸附时间、吸附温度和废水pH对Cd2+去除率的影响,并探讨了吸附机理。表征结果显示:高炉渣吸附剂具有疏松多孔的特点,表面十分粗糙,比表面积较大。实验结果表明:当吸附温度为室温(28℃)、废水pH为7、初始Cd2+质量浓度为10 mg/L、吸附剂加入量为8 g/L、吸附时间为60 min时,Cd2+去除率达到98.55%;高炉渣对Cd2+的吸附符合拟二级动力学方程和Langmuir等温吸附模型,且吸附反应易发生。     

Synthesis of hydrogarnet from molten slag and its hydrogen chloride fixation performance at high temperature

Hydrogarnet was synthesized hydrothermally below 200°C using molten slag obtained from municipal solid waste. For comparison, it was also synthesized using pure-phase CaO–Al₂O₃–SiO₂–H₂O, as reported previously. The structural and textural properties of this material were investigated using various analytical and spectroscopic techniques such as X-ray diffraction, X-ray fluorescence spectrometry, atomic absorption spectrometry (AAS), thermogravimetry/differential thermal analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The Cl⁻ fixation ability of hydrogarnet was investigated in the temperature range 500–800°C in a fixed-bed flow reactor using a HCl concentration (1000 p.p.m.v.) similar to that of incinerator exhaust gas. Under these experimental conditions, the hydrogarnet was capable of reducing the HCl gas level to less than 1 p.p.m.v. Analysis of the spent catalyst revealed that the hydrogarnet was being transformed into wadalite and CaCl₂ at high temperatures. The elution test for chromium ions in hydrogarnet obtained from slag was also used, and it was found that chromium ions were not eluted from hydrogarnet. Received: January 27, 2001 / Accepted: October 11, 2001